Polymer sensory systems

Human skin is a fascinating example of a large area sensory system, allowing us to sense temperature, humidity, touch, pressure, and vibration. Scientists are inspired by this natural model system and work on artificial electronic sensor surfaces (Lacour et al. 2005) that will ultimately enable robots with a sense of feeling (Chortos and Bao 2014 Hammock et al. 2013 Bauer et al. 2014). A full coverage of this topic is beyond the scope of this chapter, so here we focus on illustrating the huge potential for piezoelectric polymers in electronic skin development with two selected researeh examples. 

Uses. Cinnamyl alcohol and its esters, especially cinnamyl acetate, are widely employed in perfumery because of their excellent sensory and fixative properties. They are frequently used in blossom compositions such as lilac, jasmine, lily of the valley, hyacinth, and gardenia to impart balsamic and oriental notes to the fragrance. In addition, they ate utilized as modifiers in berry, nut, and spice flavor systems. The value of cinnamyl alcohol has also been mentioned in a variety of appHcations which include the production of photosensitive polymers (49), the creation of inks for multicolor printing (50), the formulation of animal repellent compositions (51), and the development of effective insect attractants (52). 

A new transduction mechanism based on the aggregation of conjugated sensory polymers induced ions as described by Swager et al. [109]. This new system displays enhanced sensitivity because of energy migration processes and has a high selectivity for over Na" ions. 

The SA sensory polymer concept was first demonstrated in an analyte-induced quenching assay (Figure la) where the ligand to the receptor site was a quencher [4]. A key feature of the polymeric system was that the exciton migration caused greatly enhanced quenching relative to a chromophore bearing only one of the receptors. This is established by... 

As mentioned above, food systems are complex multiphase products that may contain dispersed components such as sohd particles, hquid droplets or gas bubbles. The continuous phase may also contain colloidally dispersed macromolecules such as polysaccharides, protein and lipids. These systems are non-Newtonian, showing complex rheology, usually plastic or pseudo-plastic (shear thinning). Complex structural units are produced as a result of the interaction between the particles of the disperse phase as well as by interaction with polymers that are added to control the properties of the system, such as its creaming or sedimentation as well as the flow characteristics. The control of rheology is important not only during processing but also for control of texture and sensory perception. 

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